1. Field of the Invention
The present invention relates to power control systems, or more particularly, to a system to control, program and monitor an array of point-of-load regulators and other auxiliary devices.
2. Description of Related Art
With the increasing complexity of electronic systems, it is common for an electronic system to require power provided at several different discrete voltage and current levels. For example, electronic systems may include discrete circuits that require voltages such as 3v, 5v, 9v, etc. Further, many of these circuits require a relatively low voltage (e.g., 1v), but with relatively high current (e.g., 100 A). It is undesirable to deliver relatively high current at low voltages over a relatively long distance through an electronic device for a number of reasons. First, the relatively long physical run of low voltage, high current lines consumes significant circuit board area and congests the routing of signal lines on the circuit board. Second, the impedance of the lines carrying the high current tends to dissipate a lot of power and complicate load regulation. Third, it is difficult to tailor the voltage/current characteristics to accommodate changes in load requirements.
In order to satisfy these power requirements, it is known to distribute an intermediate bus voltage throughout the electronic system, and include an individual point-of-load (“POL”) regulator, i.e., DC/DC converter, at the point of power consumption within the electronic system. Particularly, a POL regulator would be included with each respective electronic circuit to convert the intermediate bus voltage to the level required by the electronic circuit. An electronic system may include multiple POL regulators to convert the intermediate bus voltage into each of the multiple voltage levels. Ideally, the POL regulator would be physically located adjacent to the corresponding electronic circuit so as to minimize the length of the low voltage, high current lines through the electronic system. The intermediate bus voltage can be delivered to the multiple POL regulators using low current lines that minimize loss.
With this distributed approach, there is a need to coordinate the control and monitoring of the POL regulators of the power system. The POL regulators generally operate in conjunction with a power supply controller that activates, programs, and monitors the individual POL regulators. It is known in the art for the controller to use a multi-connection parallel bus to activate and program each POL regulator. For example, the parallel bus may communicate an enable/disable bit for turning each POL regulator on and off, and voltage identification (VID) code bits for programming the output voltage set-point of the POL regulators. The controller may further use additional connections to monitor the voltage/current that is delivered by each POL regulator so as to detect fault conditions of the POL regulators. A drawback with such a control system is that it adds complexity and size to the overall electronic system.
It is also known in the art to include various other devices in an electronic system for system supporting functions (also referred to as auxiliary devices). These devices may provide low power regulation, such as a linear regulator, low-drop out (LDO) linear regulator or other power supplies; device switching, such as machine-operated switches, magnetically operated control switches, thermal and magnetic relays, time delay relays, and actuators; motor control; temperature control, such as blowers and fans; visual indicator devices, such as lights, light emitting diodes (LEDs), video display monitors, gauges; peripheral devices; and the like. In some cases, it is desirable to coordinate the control over these auxiliary devices in concert with the POL regulators of the power system, such as to control the operation of a fan in synchronism with activation of a POL regulator; however, conventional distributed power system do not provide flexibility to control other auxiliary devices in addition to POL regulators.
Thus, it would be advantageous to have a system and method for controlling and monitoring POL regulators and other auxiliary devices within a distributed power system.